How to Select a Camera by Form Factor
There are many different form factors available for security cameras. Box, dome and bullet are the most common shape categories, and there are different variants within each category.
For any installation, it may be beneficial to employ a spot monitor (a small NTSC video monitor that allows viewing close to the camera itself) to aid in initially positioning the camera. Some cameras, notably dome cameras which often have hidden wiring, have a dedicated spot monitor connector that can be accessed by a lone installer. Without a spot monitor, there may need to be two installers - one aiming the camera, and another at the monitoring site to report on the camera's view.
Typically are sold without a lens, or with an easily-removable lens that can be swapped for another for more specific applications. Box cameras are very versatile cameras for this reason. Most box cameras are mounted on a wall or ceiling using a camera mounting bracket. For outdoor applications, box cameras in outdoor-rated environmentally protected enclosures are available.
Box cameras are straightforward and easy to install: The mounting bracket is affixed to a wall, ceiling, or a similar structural feature, then the camera is attached to the mounting bracket. The power and video (BNC) cables are then connected. The camera's angle, zoom, and focus can then be adjusted, and when correct, locked into position. The camera is now ready for operation. In some cases, the back focusing control may require adjustment to avoid a noticeable focus change when in night mode with IR illumination.
There are many different variations: plastic domes (generally for indoor use), IP-66 rated domes (for outdoor use), vandal proof domes, PTZ (Pan, Tilt, and Zoom) domes, and so on. Domes are generally more aesthetically pleasing than box cameras, and have an inherent design benefit that makes its view unapparent to an observer. Most of the time domes are installed on the ceiling.
Installation is a bit more involved than for a box or bullet camera, but domes provide a cleaner and less-obtrusive solution. The area for installation must be decided, and power and video cables will need to be planned and routed, usually above a ceiling or behind a wall. Holes will then be made for the camera's mounting hardware, and if hidden wires are required, for the power and video cables. Many dome cameras come with paper hole templates to make proper hole-drilling location easy. The wiring (power and video) is then connected, the transparent dome is removed, and the camera is secured using its mounting screws. Once installed, check to see if there is a black liner that needs to be removed during installation, and adjust the camera module's view to the intended target using the 3-axis gimbal. If the camera includes a vari-focal and/or focusable lens, adjust the focal length and fine tune the focus using the control levers around the lens. When finished, secure the levers by twisting them finger-tight clockwise, as if tightening a screw. Replace the black liner back in the transparent dome, and affix the transparent dome to its now-mounted base. The dome camera is now ready for operation.
For an easy-to-install general purpose camera, the bullet is the way to go. The bullet is a very popular form factor because of its no-nonsense, straightforward and practical design. Most of them are IP rated for outdoor use and come with powerful weather-sealed infrared (IR) LEDs for IR illumination. Visible lighting is not needed, as a bullet camera with IR LEDs can go into "Night" mode, turning on its IR LEDs and automatically performing internal adjustments to be able to view in total darkness. Many bullet cameras have external controls so that they be manually focused and/or zoomed without the need to open the camera itself. Bullet cameras are available in a wide array of versions with different TVL resolutions, lens options, IR illumination powers and other convenient features, such as lens control mechanisms and OSD access, if present.
The bullet camera is generally the easiest type of camera to install, and they can be installed nearly anywhere. The physical mounting is normally accomplished with 3 or 4 screws, and access behind the mounting surface may not be needed. After the camera is mounted, power and video cables are connected. The camera is now functional, and all that remains is to adjust the angle of the camera and make final adjustments. The vari-focal lens and focus, if present, can often be set by external adjustment rings. Some cameras come with a tool for securely locking the rings afterward. Several bullets are furnished with an attached adjustable sun shield, and if installed outdoors, it is advisable to additionally shield them from weather, often by mounting them under an eave or awning.
More sophisticated bullet cameras come furnished with DIP switches, or even OSD (On Screen Display) menus to set up advanced camera features such as exposure control, color balance, etc. These features can be set by setting the DIP switches, using navigation pushbuttons, or even with advanced 5-way navigation control, depending on the camera model.